Renal insufficiency in community patients with mild asymptomatic microhematuria.

Primary-care physicians often must decide when patients with asymptomatic microhematuria warrant further testing for renal parenchymal disease. Because previous data had shown a greater frequency of elevated serum creatinine concentration in a population with asymptomatic microhematuria than in control subjects without hematuria, we reviewed the records of 125 patients with isolated asymptomatic microhematuria and elevated serum creatinine (AM/EC) and 83 comparison patients with no hematuria and elevated serum creatinine (NH/EC) from a previous population-based study to determine the relationship between renal parenchymal disease and isolated asymptomatic microhematuria. Serum creatinine was often elevated transiently because of volume depletion or shock, or elevations occurred in relationship to a terminal illness. Thus, only 63 AM/EC patients and 45 NH/EC control subjects had primary renal parenchymal disease or systemic disorders that caused an elevated serum creatinine. The patients selected from the asymptomatic microhematuria population because of elevated serum creatinine most often had low-grade hematuria and were typically 75 years of age or older. No disease was consistently found more frequently in the AM/EC patients than in the NH/EC group. Intervention at the time of the detection of hematuria might have altered the prognosis in 8% and probably would not have altered the prognosis in 78%. Therefore, exhaustive diagnostic testing to detect renal parenchymal diseases cannot be advised in asymptomatic elderly patients with low-grade (grade 1) microhematuria unless more specific indications are present.